do down vs pull apart

do down

verb
  • To belittle or intimidate 

pull apart

verb
  • Used other than figuratively or idiomatically: see pull, apart. 

  • to separate two people or animals that are fighting 

  • to become separated as a result of pulling 

  • to dismantle a machine or other mechanical device. 

  • to rigorously investigate the basis of an idea or theory. 

How often have the words do down and pull apart occurred in a corpus of books? (source: Google Ngram Viewer )